1. Field of the Invention
The invention relates to a hydrogen generating device, and more particularly, to a hydrogen generating device that utilizes a solid reactant.
2. Description of Related Art
Fuel cells are a power generating device that convert chemical energy into electricity. Comparing to conventional power generating devices, fuel cells have the advantages of little pollution, low noise, high energy density, and high energy conversion rates. Fuel cells could be used in fields such as portable electronics, home power generating systems, transportation, military equipment, space industry, and small power generating systems.
Each type of fuel cell is used for different application markets according to each different operating principle and environment. The application of mobile sources mainly uses a proton exchange membrane fuel cell (PEMFC) and a direct methanol fuel cell (DMFC). The two belong to low temperature starting fuel cells that use a proton exchange membrane to transmit protons to the mechanism. In the PEMFC operating principle, hydrogen in the positive pole catalyst layer undergoes an oxidation reaction, generating a hydrogen ion (H+), and an electron (e−) (PEMFC principle), or methanol and water in the positive pole catalyst layer undergoes an oxidation reaction to generate a hydrogen ion (H+), CO2, and an electron (e−) (DMFC principle), wherein the hydrogen ion could transmit to the negative pole through the proton conduction membrane, and the electron is then applied to a load for work through an outer circuit and thereafter transmits to the negative pole through the outer circuit. At this point the oxygen received by the negative electron terminal will undergo a restoring reaction with the hydrogen ion and the electron in the negative pole catalyst layer to generate water. The hydrogen fuel required by the positive pole could be obtained through the reaction between liquid reactants and solid reactants. For example, in the technique of using solid NaBH4 to store hydrogen, water is mixed and reacts with the solid NaBH4 to generate hydrogen.
That is to say, the solid NaBH4 and water bag are disposed in a casing, and the user could press a button disposed on the casing to pierce the water bag, so the water in the water bag flows out and reacts with the solid NaBH4 to generate hydrogen. The disadvantage of this method is the button and the casing are assembled as different structures. Thus when the button is pressed, there is an interstice between the button and the casing so the structure is not airtight, lowering the generation rate of hydrogen. In addition, when piercing the water bag, since the size of the pierced opening is limited, a portion of the water will remain in the water bag because of the obstruction from the water bag, and only a portion of the water will flow out and react with the solid NaBH4, lowering the generation rate of hydrogen.
Taiwan patent application no. TW200640070 and US patent application publication no. US20090029209, US20040243184 discloses technology relating to fuel cells.